Tie-member linkage for crawler tractors



Dec. 1 3, 1932.1 M, D 1,890,975

TIE MEMBER LINKAGE FOR CRAWLER TRACTORS Filed July 16. 1950 3Sheets-Sheet 1 fig zflzmfl mes: y G's: aur /#4 4; Y @5142? oyzzqys.

Dec. 13, 1932. ERDAHL 1,890,975

TIE MEMBER LINKAGE FOR CRAWLER TRACTORS Filed July 16. 1930 3Sheets-Sheet 3 Ira-denial":

A/EC 161% 12/6204 a in a corresponding position for accommodat-'Patented Dec. 13, 1932 UNITED STATES PATENT OFFICE NICHOLAI M. ERDAHL,OF EDGERTON, WISCONSIN, ASSIGNOR TO HIGHWAY TRAILER COMPANY, OFEDGERTON, WISCONSIN, A CORPORATION OF WISCONSIN TIE MEMBER LINKAGE FORCRAWLER TRACTORS Application filed July 16,

weight of the crawler units as ballast, for

counteracting forces acting in the direction to tilt the forward end ofthe vehic e chassis in an upward direction about its pivot connection tothe crawler units. It consists in certain features and elements ofconstruction in combination, as herein shown and described, as indicatedby the claims.

In the drawings:

Figure 1 is a side elevation of a vehicle embodying the presentinvention; parts being broken away to show details of construction.

Figure 2 is a front elevation showing the crawler units indicated indotted outline.

Figure 3 is .a plan view of the supporting or supplementary frame, withthe crawler units indicated in dotted outline.

Figure 4 is a view similar to Figure 2, showing one of the crawler unitstraversing a rise in the road bed; and showing the mechanism ing thesame.

Figure 5 is a more or less diagrammatic view in side elevation withparts of the chassis omitted. s

Figure 6 is a rear end elevation of the vehicle with parts broken awayto show details of construction.

The vehicle illustrated in the drawings includes a chassis, 10, carryingthe usual power plant encased in the housing, 11, and all supported on apair of transversely spaced driving crawler units. 12. These crawlerunits are pivotally connected to the vehicle chassis adjacent their rearends, with the forward or opposite ends of said crawler units floatingwith respect to the chassis. The floating ends of the crawler unitssupport the 1930. Serial No. 488,333.

porting members, 15, of the crawlers, 12; this connection also serves tosupport the rear end of the chassis on said crawlers. It may beunderstood that the vehicle is provided with means concentric with thepivotal connection, 13, for driving the rear driving wheels, 17, of thecrawlers in any conventional manner. The floating ends of the units areprovided with idler wheels, 19, and trained around the respective pairsof driving and idler wheels of each crawler unit is a flexible trackbelt, 20, for engaging the road surface.

Ordinarily, when vehicles of this character are employed for straighthorizontal draft work, the problem to which the present invention isdirected does not present itself,

since the vehicle is so constructed as to be substantially balanced atall times against the normal horizontal draft stresses, and the pivotalconnection between the crawler units and the chassis permits of afloating action at the ends of the crawlers for accommodating road bedirregularities.

A supplemental or supporting frame struc ture, indicated generally at25, is of rectanguborin device as indicated encrall r at A' z: a v

As illustrated, the derrick includes a power operated draft cable, B,associated with a winding drum, C, which is connected to the power plantor other power source for lifting material. Because of such anarrangement, that is, the location of the derrick rearward of the pivotshafts, 13 and 2(5,

it is essential to provide proper balance of the load being lifted bythe derrick, and for this purpose a positive connection is providedbetween the front end of the chassis, the frame, 25, and the floatingends of the crawler units, so as to employ the weight of the crawlerunits as ballast for counteracting the downward stresses acting on therear extension of the frame, 25; thus enabling said extension to carrygreater loads, for example, to permit the derrick to lift greaterweights.

For this purpose the forward ends of the side members, 27, are rigidlysecured together by a transverse tie member, 29, centrally of which ispivotally connected about a horizontal longitudinal axis, 30, atransversely disposed compensating beam, 31, which is vertically offseta substantial distance above the side members, 27', as seen in Figure 2.Pivotally connected to the outer ends of said beam are a pair ofsubstantially vertically disposed connecting links, 32, whose lower endsare pivotally connected to the outer ends of a pair of side links, 33,which are disposed substantially within the vertical limits of the sidemembers, 27, and are pivotally connected thereto at 34 at a pointadjacent the middle of the length of said side members. The links 32, asmay be seen in the drawings, serve as knuckle connections between theside links, 33, and the compensating beam, since the movements of thebeam and the links are substantially perpendicular to each other. Theside links, 33, are guided in their vertical movement about theirpivots, 34. by a pair of spaced bars, 36, which are rigidly secured tothe side members, 27, of the supporting frame.

These side links, 33, are positively connected to the floating ends ofthe respective crawler units by vertically disposed thrus't links, 39,the ends of which are pivotally connected to the respective elements soas to compensate for some slight longitudinal movement relative to eachother. Thus. when one of the crawler units trav rses a rise on the roadbed, as indicated at D in Figure 4, the frame structure. 15. of thecrawlerelement imparts a force through the thrust member, 39, in anupward direction, swinging the corresponding side link, 33, upwardlyabout its pivot, 34, and by reason of its connection to the link, 32,forces the adjacent end of the compensating beam, 31, upwardly also.

By virtue of this action the vehicle chassis erses a rise in the roadbed, it will be understood that the transverse spring, 14, must besufliciently flexible so as not to act as a lever to raise the chassiswhen one end of the spring is forced to rise with the rising crawlerunit.

In order to cushion the shocks and impact of the chassis, by itsmovement relative to the crawler units, and to check the rebound due tothe action of the spring, 14, I provide a pair of coil springs, 41 and42, at opposite sides of the front end of the chassis, arranged oneabove and one below fixed lugs, 43, on said chassis. Each pair ofsprings is mounted on a rod,'44, whose lower end is pivoted at 45 to abracket, 46, carried on the side frame members, 27, and the rod isprovided with adjustable stop shoulders, 47 and 48, arranged forengaging the oppositev ends of the respective springs. It will now beapparent that by reason of this construction the pair of upper springs,41, on opposite sides of the chassis power plant will assist the leafspring, 14, for yieldingly supporting the chassis on the crawler units,while the pair of lower coil springs, 42, act more or less as snubbersfor counteracting and absorbing rebound or movement of the chassis in anupward direction with respect to the supporting frame structure, 25. Itwill be apparent that severe shocks which are frequently imparted to thechassis by reason of the rebound action, are

substantially eliminated, so that the vehicle will ride smoothly and ona comparatively even keel.

I claim 1. In combination with a vehicle chassis, a pair of transverselyspaced crawler units pivotally connected adjacent one end to saidchassis, spring means located at a distance from said pivot foryieldingly supporting" the other end of the chassis on the crawlerunits, a supporting frame pivotallv connected to the chass s above saidpivot of the crawlers, and having a'rearward extension beyond saidpivots, and means for connecting the other end of said frame to thecrawler units at the end remote from their pivot connection to thechassis.

.2. In the combination defined in claim 1. said means being directlyconnected to the crawler units so as to permit employing the 'same asballast for counteracting relatively great downward stresses on saidextension of the frame.

3. In combinatlon with a vehicle chassis, a palr of transversely spacedcrawler units pivotally connected adjacent one end to said chassis,spring means located at a distance from said pivot for yieldinglysupporting the other end of the chassis on the crawler units, asupporting frame pivotally connected to the chassis at the end adjacentthe pivot to the crawlers, said frame includingra pair of longitudinallyextending side members, and a tie connecting said members at the endremote from the pivot, a pair of links pivoted at one end to said sidemembers, a transversely disposed beam pivoted to said tie of the frame,means pivotally connected to the other ends of said links and the end ofsaid beam, and means directly connecting said links to the adjacentcrawler units.

4. In the construction defined in claim 3, said last mentioned meansbeing pivotally connected to said crawler units and links to accommodatesaid supporting frame to the crawler units.

5. In the construction defined in claim. 3, means carried on the sidemembers of the frame for guiding said links throughout their range ofswinging movement.

6. In combination with a vehicle chassis, a pair of transversely spacedcrawler units pivotally connected ad acent one end to said chassis,spring means located at a distance from said pivot for yieldinglysupporting the other end of the chassis on the crawler units, asupporting frame pivotally connected to the chassis at the end adjacentthe pivot to the crawler units, said frame including a pair oflongitudinally extending side members having portions extendingrearwardly of said pivot, and a tie member connecting the opposite endsof said side members, said extensions being arranged to support a loadwhich may tend to swing the forward end of the frame upwardly about itspivot, a pair of side links pivotally connected at one end to said sidemembers about horizontal axes, a transversely dis osed beam pivotallyconnected adjacent its middle to the tie member for swinging about ahorizontal longitudinal axis, floating links having their ends pivotallyconnected respectively to the ends of said links and to the ends of saidbeams, and members directly connecting said side links intermediatetheir ends to the adjacent crawler unit, whereby said crawler unitsserve as ballast for counteracting the tendency of the forward end ofthe frame to swing upwardly about its pivot.

7. In combination with a vehicle chassis, a

- pair of transversely spaced crawler units pivthe crawler units, asupporting frame pivotally connected to the chassis ad acent the pivotof the crawlers, means positively connecting the end of the frame to thecrawler units at the end remote from the respective pivots, andindependent means providing a flexible connection between said remoteend of the frame and the chassis.

8 In combination with a vehicle chassis, a pair of transversely spacedcrawler units pivotally connected adjacent one end to said chassis,spring means located at a distance from said pivot and arranged foryieldingly supporting the other end of the chassis on the crawler units,a supporting frame pivotally connected to the chassis ad acent the pivotof the crawlers, means positively connecting the end of the frame to thecrawler units at the end remote from the respective pivots, andadditional spring means interposed between the frame at the end remotefrom its pivot, and the chassis, adapted for cushioning verticalmovement of one of the parts relative to the other,

9. In combination with a vehicle chassis, a pair of transversely spacedcrawler units pivotally connected adjacent one end to said chassis,spring means located at a distance from said pivot and arranged foryieldingly supporting the other end of the chassis on the crawler units,a supporting frame pivotally connected to the chassis adjacent the pivotof the crawlers, means positively connecting the end of the frame to thecrawler units at the end remote from the respective pivots, and meansproviding a flexible connection between said remote end of the frame andthe chassis, said means including a vertically disposed rod pivotallyconnected to one of said elements, and a pair of oppositely reactingcoil springs carried on said rod and reacting against a fixed stop onthe other of said elements.

10. In combination with a vehicle chassis, a pair of transversely spacedcrawler units pivotally connected adjacent one end to said chassis,spring means located at a distance from said pivot and arranged foryieldingly supporting the other end of the chassis on the crawler units,a supporting frame pivotally connected to the chassis adjacent the pivotof the crawlers, means positively connecting the end of the frame to thecrawler units at the end remote from the respective pivots, and meansproviding a flexible connection between said remote end of the frame andthe chassis,

Ill

said means including a vertically extending rod pivoted at its lower endto said frame, a pair of oppositely reacting coil springs carried onsaid rod and a fixed stop on the chassis interposed between saidsprings.

11. In combination with a vehicle chassis, a pair of transversely spacedcrawler units pivotally connected adjacent one end to said chassis, asupporting frame including a pair of longitudinally extending sidemembers piv otally connected to the chassis about a transverse axis;means positively connecting the side members of the frame to the crawlerunits at the end remote from their pivot connection to the chassis, andspring means located at a distance from said pivot connection of thechassis and crawler units and arranged for yieldingly supporting thefree end of the chassis on the crawler units independently of the suporting frame.

12. n combination with a vehicle chassis, a pair of transversely spacedcrawler units pivotally connected adjacent one end to said chassis, a suporting frame including a air of longitudinally extending side mem ersmy hand at Edgerton,

pivotally connected to the chassis about a transverse axis; meansdirectly connecting the side members of the frame to the crawler unitsat the end remote from their respective pivot connections and arrangedfor permitting a limited range of vertical movement of one crawler unitrelative to the other for accommodating roadbed irregularities, andspring means located at a distance from said pivotal connection of thechassis and crawler units and arranged for yieldingly supporting theother end of the chassis on the crawler units independently of thesupporting frame.

In testimonywhereof I have hereunto set Wis., this 9th day of NICHOLAIM. ERDAHL.

July, 1930.

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